Scissors jack



y 2, 1967 w. J. STEPPON 3,317,187

SCISSORS JACK I I 2 Sheets-Sheet 1 Filed Feb. 7, 1966 INVENTOR WILLIAMJ. STE PPON 16.3 V W W ATTORNEYS y 2, 1967 w. J. STEPPON 3,317,187

SGISSORS JACK Filed Feb. 7, 1966 2 Sheets-Sheet 2 INVENTOR WILLIAM J.STEPPON @AWWQWS ATTORNEYS U *d s P 3,317,187 H1116 t3IS 2ltI1t C Vpatented May 2, 1967 FIG. 1 is an elevational, perspective view of ascissors 3,317,187 jack in accord with the invention shown in thepartially SCISSORS JACK William J. Steppon, Jackson, Mich., assignor toRyerson & Haynes, I'nc., Jackson, Mich, a corporation of Michigan 'FiledFeb. 7, 1966, Ser. No. 525,588 9 Claims. (Cl. 254-126) The inventionpertains to load lifting devices and particularly relates to scissorjacks.

Jacks of the scissors type wherein a plurality of pivotallyinterconnected links are adjusted by means of a screw have recentlyfound increased usage with automobiles as emergency equipment for tirechanging. Scissor jacks may be employed directly below the vehicleundercarriage, are of compact storage size and configuration, and aresimple to use, yet dependable in operation. While an automobile jackused for the purpose of changing tires is usually operated only a fewtimes during its life, the jack must be dependable and safe in operationand operable at all times, and the scissors-type jack has beenexperiencing increased popularity as standard equipment with newautomotivetype vehicles.

It is an object of the invention to provide a scissors jack which may beused with automotive-type vehicles wherein the jack is of a rugged, highstrength construction, dependable and safe in use, may be readilymanufactured and assembled, and may be constructed from economicallyproduced components.

Another object of the invention is to provide a scissors jack ofunusually high strength, wherein one of the links of the jack is formedof an elongated member having a channel configuration, and wherein oneend of this member defines a yoke and the other end thereof forms aconvex bearing surface for sliding cooperation with the jack load rest.

An additional object of the invention is to provide a scissors jackemploying a load rest which is pivotally mounted to one set of links ofthe jack and is slidably engaged by the end of another jack link, andthe load rest is of such a configuration that extra lift or elevation ofthe load rest is obtained as the jack approaches its maximum elevationposition.

A further object of the invention is to provide a linkage for a scissorsjack which is of an integral channel-shaped, transverse cross sectionand includes a convex bearing surface at one end. The bearing surface ofthe formed link is manufactured by economical stamping procedures, andis of high strength characteristics, and includes a hinge portionsupported on its end by side portions of the channel member.

Yet another object of the invention is to provide a method of forming achannel-shaped-scissors jack link having a convex bearing surface at oneend wherein the bearing surface is defined by a tongue formed from thebase portion of the channel configuration, and the tongue is supportedby the leg portions of the channel configuration.

Another object of the invention is to provide a scissors jack link of achannel-shaped, transverse cross section wherein one end of the link isin the shape of a yoke and each of the yoke portions includes a pivotpin receiving opening. The pivot pin receiving opening includes a throator entrance portion which intersects an edge of the associated yokeportion permitting ready assembly of the link to the jack structure.Additionally the yoke portion includes a deformable portion wherein apivot pin may be locked Within the pin receiving recess once the link isproperly assembled to the pivot' pin.

These and other objects of the invention arising from the details andrelationships of the components of an embodiment thereof will beapparent from the following description and accompanying drawingswherein:

elevated position, portions of the structure being cut away for purposesof illustration,

FIG. 2 is an elevational view of a scissors jack in accord with theinvention when fully retracted, a portion of the load rest mountinglinkage being cut away to illustrate the relationship of the load restto the pivot stud,

FIG. 3 is an enlarged, detail, elevational, sectional view of the loadrest and associated links during elevation in accord with the invention,

FIG. 4 is a side elevational view of the formed channel jack link inaccord with the invention,

FIG. 5 is a plan view of the link of FIG. 4,

FIGS. 6, 7 and 8 are elevational, sectional views taken through the linkof FIG. 4 along sections VIVI, VII VH, and VIII-VIII, respectively,

7 FIG. 9 is a plan view of the end of the blank from which thechannel-shaped link of FIG. 4 may be formed, prior to folding of theblank, and

FIG. 10 is an elevational, detail view of a modification of pivot pinreceiving opening and throat defined in a yoke portion. 7

The arrangement of the components of a scissors jack in accord with theinvention will be appreciated from FIGS. 1 and 2. The jack includes abase 10 preferably formed of a sheet material fabricated by a stampingand bending operation. The base 10 includes a substantially horizontallydisposed portion 12 from which depend vertically extending spaced wallportions 14. A pair of spaced, parallel pivot pins 16 and 18 are mountedon the base wall portions 14 and extend thereacross. The pivot pin 16serves as the support for the jack link 20 and the pivot pin 18 supportsthe jack link 22. The link 20 and the link 22 each consists of a pair ofspaced, parallel, stamped metal elements 24 and 26, respectively, havinga lower end through which the associated pivot pin extends. The pivotpins are each provided with a sleeve spacer 28 circumscribing thecentral region of the pivot pin to maintain the spacing and separationof the elements of a common link. As is the usual practice, the lowerends of the link elements of the links 20 and 22 are each provided withmeshing gear teeth 30, whereby pivoting of the links with respect to thebase 10 is controlled, and the links 20 and 22 will pivot in an equalmanner relative to the base during operation of the jack.

The jack also includes a link 32 and a link 34, each having an upper endand a lower end. The link 32 consists of a pair of stamped, parallelelements 36 and the link 34 is of a channel transverse cross-sectionalconfiguration which will be more fully described later. The lower end ofthe link 34 is formed as a yoke defined by a pair of spaced linkportions 38.

The upper ends of the link elements 24 are pivotally mounted upon pivots40 extending from opposite ends of a block 42 interposed between thelink elements, FIG. 1. H FIG. 1 only one of the pivots 40 is shown, inthat the other extends away from the viewer. The lower end of each ofthe link elements 36 is provided with a hole through which a pivot 40extends, and the pivots 40 are swaged at 44 to maintain the linkelements 24 and 36 thereon in a pivotal manner.

The link elements 26 are pivotally mounted upon pivots 46 extending fromthe end surfaces 48 of a block 50. Also, the yoke portions 38 of thelink 34 are disposed adjacent the block surfaces 48 and are formed withan opening for receiving the pivots 46. In this manner it will beappreciated that the upper end of the link 20 is pivotally connected tothe lower end of the link 32, and the upper end of the link 22 isconnected to the lower end of the link 34.

The block 50 is provided with a bore through which the cylindrical shank52 of an adjusting screw 54 extends. The adjusting screw 54 has ahexagonal head 56 defined on the outer end thereof, and a thrust bearingis interposed between the head 56 and the block 50. The thrust bearing,preferably, consists of a pair of steel washers 58 having a nylon washer60 inserted therebetween. The adjusting screw shank portion 52 may bestaked, or otherwise provided with means disposed adjacent the inside ofblock 50, to prevent axial movement of the adjusting screw relative tothe block but permit rotation of the screw relative thereto. The block42 includes a threaded bore 62 through which the threaded portion of thescrew shaft 54 extends.

The link elements 36 pass on each side of the link 34 and a pivot stud64 extends through holes in the link elements 36 and the link 34 topivotally connect the links 32 and 34 together.

The upper end of the link 32 is provided with a pivot pin 66 upon whichthe channel-shaped load rest 68 is pivotally mounted. The load rest 68includes a base portion 70 from which depends side portions 72 which arein spaced, parallel relation to each other. The load rest base portion70 is of a nonplanar, concave configuration, as will be apparent fromFIG. 3, and includes a convex undersurface 74 adapted to be slidinglyengaged by the upper end of the link 34. The load rest base portion 70is of a configuration wherein when the ends of the load rest aresubstantially horizontally related, the lowermost portion of the baseportion underside as represented at 76 occurs well toward the pivot pin66 with respect to the right load rest end, FIG. 3. The purpose of theconvex configuration of the load rest surface 74 is to increase theelevation of the load rest base portion as the jack approaches itsmaximum elevation, and this operation will be more fully described laterin the specification.

With some vehicles it is desirable that a frame engaging saddle beaffixed to the load rest, and such a saddle is shown in dotted lines inFIG. 3. The saddle 78 may be of sheet material and includes a groove 80in which a rib or projection defined on the underside of the vehiclebody may be received.

The link 34 is of a channel-shaped, transverse cross section including abase portion 82 from which dpeends lateral side portions 84 terminatingin side edges 86. A longitudinally extending depression is, preferably,formed in the base portion 82 for increasing the resistance of the linkto bending. The link side portions 84 are each formed with a hole 88intermediate the ends of the link for receiving the pivot stud 64.Adjacent each of the holes 88 defined in the side portions, the sideportions are deformed outwardly at 90 to define outer edges which serveto space the link elements 36 when the jack is assembled.

The lower end of the link 34, as previously mentioned, is defined by ayoke formed from extensions of the side portions 84 to form yokeportions 38 which are outwardly related to the side portions 84. Each ofthe yoke portions 38 is formed with an end edge 92 and a lower edge 94which lies on the same plane as the side portion edges 86. An opening 96is defined in each of the yoke portions 38 and is preferably of acircular configuration capable of receiving a pivot 46 of the block 50.A slot, or throat 98, is defined in the yoke portions 38 intersectingthe end edge 92. The throat 98 is of a normal transverse dimensioncapable of slidably receiving the pivots 46 whereby the yoke may beassembled to the block 50. After the yoke side portions 38 have beenslipped over the pivots 46, the yoke is deformed by swaging, or similaroperation, in a direction indicated by the arrows 100, FIG. 4, to reducethe transverse dimension of the throat 98 to such a dimension as toprevent the pivots 46 from leaving the openings 96 and entering into thethroat whereby the yoke could be removed from the pivots. After the yokeportions 38 have been deformed, the yoke will be permanently connectedto the pivots 46, yet a pivot interconnection between the link 34 andthe block 50 will be maintained as the pivots will be rotatably receivedwithin the circular openings 96.

As the upper end of the link 34 is adapted to slidingly engageundersurface 74 of the load rest base portion 70, the link upper end isprovided with a convex bearing surface 102 which is capable of engagingthe load rest undersurface without galling or otherwise damaging theload rest. To provide the convex bearing surface at the upper end of thelink 34, a portion of the link member base portion 82 is arcuately bentfrom the general plane of the base portion in the direction of the sideportions 84. The side portions 84 are each formed with a longitudinallyextending shoulder 104 immediately adjacent their ends 106 which issubstantially parallel to the general plane of the base portion, and asurface 108 is formed in each side portion which intersects the shoulder104. The surface 108 is perpendicularly disposed to the longitudinallength of the link, and is located inwardly of the associated end 106 ofthe side portion a distance substantially corresponding to the thicknessof the portion of the base portion which is bent toward the sideportions. The end 110 of the bent base portion 112 engages the shoulders104, and the underside thereof engages the surface 108 whereby therelationship which will be apparent from FIGS. 3, 4 and 8 is produced.It will be noted that portion 112 is of a width adjacent its end 110equal to the normal width of the link 34. In this manner the convexportion 112 is firmly supported and will maintain its arcuate form todefine bearing surface 102 even under heavy loads.

A manner of forming the upper end of the link member 34 is illustratedin FIG. 9. The link 34 may be formed from flat sheet steel which isfolded to the channel-shaped configuration of the link. When the link 34is formed in this manner, the arcuate end thereof is formed as shown inFIG. 9 prior to the link being bent into the channel shape. Prior toforming the end of the link, the link blank 114 would have a rectangularend configuration as represented by the dotted lines 116, FIG. 9. Theblank 114 is placed within a die and is notched adjacent the end on bothsides of the blank central region to define a pair of notches 118. Thenotches 118 form parallel surfaces 120 which define the maximum width ofthe tongue 122. Surfaces 124 define the minimum width of the tongue, andthe surfaces 120 and 124 on each side of the tongue are interconnectedby an inclined surface 126. Arcua-tely formed surfaces 128 intersect thesurfaces 124 and intersect the surfaces 108 which are perpendicularlydisposed to the longitudinal axis of the blank. The shoulder surfaces104 are disposed parallel to each other and to the longitudinal axis ofthe blank. The ends of the side portions are defined by the surfaces106, as described above, and the end of the tongue constitutes end 110.After the blank is shaped as shown in FIG. 9,. the blank is folded alonglongitudinally extending dotted lines 130 to the channel configuration,whereby the side portions 84 are disposed in a substantially parallelrela-' tion on a common side of the general plane of the central baseportion 82. The tongue 122, which forms base portion 112, is then benttoward the shoulders 104 to engage the shoulders 104 and surface 108, asshown in FIGS. 3, 4 and 8. The formation of the convex link end does notrequire welding or other secondary operations after the portion 112 isbent into engagement with the shoulders 104 and surfaces 108. As will beapparent from FIGS. 5 and 8, the width between the surfaces 120corresponds to the width of the link end and a clean appearing andeffective convex bearing surface is provided which is capable ofwithstanding the loads which will be imposed thereon during ordinaryservice.

Extension and retraction of the jack is produced by rotating the screw54 by means of a wrench applied to the hexagonal head 56. Normally, thethreads of the screw will be of a right hand whereby clockwise rotationof the screw draws the blocks 42 and 50 toward each other to extend thejack and raise the load rest 68 relative to the base 10. When the screw54 is rotated the maximum degree in the counterclockwise direction, thejack will assume the retracted and compact relationship shown in FIG. 2.In FIG. 2 a portion of a link element 36 is broken away to illustratethe presence of the notch 132 defined in each of the side portions 72 ofthe load rest which provides clearance for the pivot stud 64 and theoutwardly formed spacer deformations 90 formed on the link 34 adjacentthe pivot stud holes 88.

As the jack is extended from the position shown in FIG. 2 toward theextended position, it will be appreciated that the link 34 will sliderelative to the load rest 68. In the fully retracted position of FIG. 2,the convex end of the link 34 extends substantially beyond the load restand as the jack is extended, the load rest undersurface 74 will slidealong the link base portion 82. As the jack approaches its maximumextension, the arcuate, convex bearing surface 102 will engage the loadrest undersurface 74, as shown in FIG. 3. Preferably, the undersurface74 is lubricated to minimize the friction between the load restundersurface and the convex bearing surface. Further extension of thejack from the position shown in FIG. 3 causes the convex bearing surface102 to approach and ride on the downwardly depressed portion 76 of theload rest base portion as the convex bearing surface approaches thepivot pin 66. The downwardly depressed portion 76 will cause anincreased counterclockwise pivoting of the load rest 68 about the pivotpin 66, FIG. 3, in an upward manner even though little relative slidingmovement between the convex bearing surface and the load restundersurface takes place. Thus, the presence of the downwardly deflectedload rest portion 76 permits an extra elevation of the load rest 68which would not be possible if the load rest base portion were of aplanar configuration.

In FIG. a modification of the formation of the pin receiving openingandthroat defined in the yoke portions 38 of the link 34 is shown. In FIG.10 the pivot pin circular opening 134 is located with respect to theassociated yoke portions at the same location as the embodiment of FIG.4. However, the pin receiving slot or throat 136 defined by the surfaces138 intersects the lower edge 94 of the yoke portions 38', rather thanthe end 92' thereof, as in the embodiment of FIG. 4. The yoke employedin the embodiment of FIG. 10 is placed on the pivots 46 in the samemanner as previously described and after assembly to the pivots 46, theyoke portions 38' are subjected to a force as indicated by the arrow 140to reduce the dimension of the space separating the throat surfaces 138and, thus, retain pivots 46 within the circular openings 134.

It will be appreciated that in accord with the invention the link 34 hashigh strength characteristics. By utilizing the channel-shapedconfiguration, high resistance to bending of the link 34 is achievedeven though the link may be formed of #7 gauge hot rolled sheet steel.The yoke construction at one end of the link permits the link to bereadily aflixed to the pivots of the block 50 and the pivot receivingopenings and throat defined therein simplify assembly. The constructionof the integral convex bearing surface 102 reduces fabrication costs, inthat extra material is not required and, yet, an effective nongalling,convex bearing surface is achieved. The support of the bearing surfaceon the shoulders 104 and surfaces 108 adequately supports the convexbearing surface defining portion 112, and scissor jacks constructed inaccord with the invention have continued to operate successfully wellbeyond the required number of cycles during life determination tests.

It is appreciated that various modifications to the disclosed embodimentmay be apparent to those skilled in the art without departing from thespirit and scope thereof, and it is intended that the invention belimited only by the following claims.

I claim:

1. A scissors jack comprising,

(a) a base,

(b) first and second links pivotally mounted on said base, each of saidlinks having a first end and a second end, said links first ends beingpivotally mounted on said base,

(c) third and fourth links each having first and second ends,

(d) pivot means pivotally connecting said second end of said first linkto said first end of said third link and pivot means pivotallyconnecting said second end of said second link to said first end of saidfourth link,

(e) screw adjustment means interposed between said first and third linksand said second and fourth links adapted to vary the spacing betweensaid second ends of said first and second links,

(f) said fourth link constituting an integral, inverted channel-shapedmember having a yoke defined at said first end thereof and a convexsurface defined at said second end thereof,

(g) a pivot stud pivotally interconnecting said third and fourth linksintermediate said first and second ends thereof, and

(h) a load rest pivotally mounted on said second end of said third link,said load rest having a fourth link engageable surface, said fourth linksecond end convex surface slidably engaging said load rest surface.

2. In a scissors jack as in claim 1 wherein:

(a) said pivot means pivotally connecting said second end of said secondlink and said first end of said fourth link comprises a spacer blockhaving spaced end surfaces, a pivot extending from each of said endsurfaces,

(b) said fourth link yoke including a pair of spaced yoke portionsreceiving said spacer block therebetween whereby each yoke portion isdisposed adjacent a block end surface, and

(c) a slot defined in each of said yoke portions receiving the pivotextending from the adjacent spacer block end surface.

3. In a scissors jack as in claim 2 wherein:

(a) said first, second and third links each comprise a pair of parallel,spaced link elements,

(b) said pivots extending from said spacer block each being pivotallyconnected to the second end of a second link element.

4. In a scissors jack as in claim 2 wherein:

(a) said slot defined in each of said yoke portions includes a pivotreceiving opening of a partially circular configuration and a pivotentrance portion intersecting an-edge of the associated yoke portion andintersecting said pivot receiving opening, said yoke portions beingdeformed upon said pivots being received within said slots pivotreceiving opening to reduce the transverse dimension of said slots pivotentrance portions preventing said pivots from being removed from theassociated slots pivot receiving openings.

5. In a scissors jack as in claim 1 wherein:

(a) said load rest fourth link engageable surface comprises anundersurface of a convex configuration whereby movement of said fourthlink convex end on said undersurface toward the load rest pivotconnection of said load rest on said third link moves the fourth linkconvex surface over the portion of said undersurface disposed nearest tosaid base.

6. In a scissors jack as in claim 1 wherein:

(a) said fourth link includes a base portion and spaced, parallel sideportions depending from said base portion, said side portions adjacentsaid fourth link in combination,

second end each being notched to define a shoulder facing in thedirection of said base portion, said base portion adjacent said fourthlink second end being separated from the adjacent side portions andhaving an end and being bent toward said side portions notches wherebysaid base portion end engages said side portions shoulders, said bentbase portion defining said convex surface at the second end of saidfourth link.

7. A link for a scissors jack comprising,

(a) an elongated channel member having first and second ends, saidmember including a base portion and spaced side portions depending fromsaid base portion,

(b) a yoke defined at said first end of said member, said yoke beingformed by extensions of said side portions longitudinally extendingbeyond the termination of said base portion adjacent said first end,

(c) a pivot receiving opening defined in each of said portions definingsaid yoke, said openings being in opposed relation to each other,

((1) means dissassociating said side portions from the base portionadjacent said member second end whereby said side portions each includea free longitudinally extending end and said base portion defines atongue having an end transversely disposed to the length of said member,and

(e) a shoulder defined on each of said second end side portions adjacentthe free end thereof, said shoulders facing toward said base portiontongue, said base portion tongue being arcuately bent to engage the endthereof with said shoulders whereby said tongue forms a convex bearingsurface.

8. In a link for a scissors jack as in claim 7:

(a) said member portions defining said yoke each having an end edgetransversely disposed to the longitudinal axis of said member and a sideedge lying in a plane substantially parallel to the member longitudinalaxis,

(b) said pivot receiving openings including an enlarged portion and athroat portion intersecting one of said yoke portion edges andintersecting the associated opening enlarged portion, said throatportion being of lesser transverse dimension than the associated openingenlarged portion and defining a deformable portion on said associatedyoke portion.

9. In a link for a scissors jack as in claim 7:

(a) a pivot stud opening defined in each of said side portionsintermediate said first and second ends, said pivot stud openings beingin opposed coaxial relation having an axis perpendicularly related tothe member longitudinal axis,

(b) said side portions surrounding said pivot stud openings beingdeformed outwardly with respect to said member defining spacer meansadjacent said pivot stud openings.

References Cited by the Examiner UNITED STATES PATENTS 1,954,558 4/1934Conrad 254126 2,071,470 2/1937 Marlowe 254-l26 3,203,670 8/1965 Farris254-122 3,259,369 7/1966 Gridley 254-122 WILLIAM FELDMAN, PrimaryExaminer. OTHELL M. SIMPSON, Examiner.

1. A SCISSORS JACK COMPRISING, IN COMBINATION, (A) A BASE, (B) FIRST ANDSECOND LINKS PIVOTALLY MOUNTED ON SAID BASE, EACH OF SAID LINKS HAVING AFIRST END AND A SECOND END, SAID LINKS'' FIRST ENDS BEING PIVOTALLYMOUNTED ON SAID BASE, (C) THIRD AND FOURTH LINKS EACH HAVING FIRST ANDSECOND ENDS, (D) PIVOT MEANS PIVOTALLY CONNECTING SAID SECOND END OFSAID FIRST LINK TO SAID FIRST END OF SAID THIRD LINK AND PIVOT MEANSPIVOTALLY CONNECTING SAID SECOND END OF SAID SECOND LINK TO SAID FIRSTEND OF SAID FOURTH LINK, (E) SCREW ADJUSTMENT MEANS INTERPOSED BETWEENSAID FIRST AND THIRD LINKS AND SAID SECOND AND FOURTH LINKS ADAPTED TOVARY THE SPACING BETWEEN SAID SECOND ENDS OF SAID FIRST AND SECONDLINKS, (F) SAID FOURTH LINK CONSTITUTING AN INTEGRAL, INVERTEDCHANNEL-SHAPED MEMBER HAVING A YOKE DEFINED AT SAID FIRST END THEREOFAND A CONVEX SURFACE DEFINED AT SAID SECOND END THEREOF, (G) A PIVOTSTUD PIVOTALLY INTERCONNECTING SAID THIRD AND FOURTH LINKS INTERMEDIATESAID FIRST AND SECOND ENDS THEREOF, AND (H) A LOAD REST PIVOTALLYMOUNTED ON SAID SECOND END OF SAID THIRD LINK, SAID LOAD REST HAVING AFOURTH LINK ENGAGEABLE SURFACE, SAID FOURTH LINK SECOND END CONVEXSURFACE SLIDABLY ENGAGING SAID LOAD REST SURFACE.